detaching comprehensions

[bob gailer]

I don't know whether you wanted a reply, since you did not ask for one. 
I am not even sure what your point is. See other comments below.

On 9/8/2017 4:24 PM, Stefan Ram wrote:
>    Maybe you all know this, but to me this is something new.
>    I learnt it by trial and error in the Python 3.6.0 console.
>
>    Most will know list comprehensions:
>
> |>>> [ i for i in range( 3, 5 )]
> |[3, 4]
>
>    I found out that the comprehension can be detached from the list:
>
> |>>> k =( i for i in range( 3, 5 ))
>
>    but one must use an extra pair of parentheses around it in the
>    assignment.
>
>    Now I can insert the "generator" »k« into a function call,
>    but a spread operator should cannot be used there.
>
> |>>> sum( k )
> |7
>
>    »sum« expects exactly two arguments, and this is what »k«
>    provides.
Where did you get that idea. If you look at the docs you will see:

"sum(iterable[, start])
Sums start and the items of an iterable from left to right and returns 
the total. start defaults to 0."

sum expects 1 or 2 arguments; when you write sum(k) you are providing 1 
argument.
>
>    But to insert it again into the place where it was "taken
>    from", a spread operator is required!
>
> |>>> k =( i for i in range( 3, 5 ))
> |>>> [ *k ]
> |[3, 4]
"taken from"??
k is a generator object.

Clear?
Bob Gailer